Florida Dye Shell (also known as the Atlantic Dye Murex or Tinted Rock Shell)
Phylum: Mollusca; Class: Gastropoda; Order: Neogastropoda; Family: Muricidae; Genus: Stramonita; Species: S. floridana · Muricidae (Murex or Rock Snail family) · Gastropod (univalve/snail). This is a whole shell with a fusiform/sub-ovate spiral shape.
Species
Stramonita floridana
Shell Type
Gastropod (univalve/snail). This is a whole shell with a fusiform/sub-ovate spiral shape.
Family
Muricidae (Murex or Rock Snail family)
Size
Approximately 1 to 1.25 inches. This is a typical adult size for this species, which generally ranges from 0.75 to 2 inches.
Color & Pattern
Overall grayish-tan to muddy brown with a slightly weathered appearance. It features darker brown or charcoal spots on the nodes/ribs. The interior aperture (though not fully visible) typically features an orange or salmon-tinted throat, characteristic of this genus.
Rarity
Common. It is a frequent find on South Carolina beaches, particularly near rock groins, jetties, or oyster beds.
Habitat
Found in intertidal and shallow subtidal zones. They prefer hard substrates like rocks, jetties, oyster reefs, and pilings where they can find prey.
Geographic Range
Western Atlantic, ranging from North Carolina south through Florida and the Gulf of Mexico to the Caribbean.
Description
A sturdy, thick-walled shell with a short spire and a large body whorl. The surface is sculpted with several prominent spiral cords and vertical undulations or 'knobs' that create a bumpy texture. The outer lip is usually thickened and slightly crenulated.
Key Features
The presence of dark spots on the raised spiral ribs, the thick and rugged texture, and the distinctive sub-ovate shape with a short, pointed spire. Its orange-tinted aperture (if visible) is a hallmark of the 'Dye Shell' group.
Collector Value
Minimal monetary value ($1–$3), but excellent for educational collections and aquarium decor. Its value lies in its representation of local Carolina coastal ecology rather than rarity.
Condition Notes
Fair to Good. The shell shows significant beach wear and 'tumbled' erosion, which has smoothed the finer sculptural details. There is some minor pitting and evidence of sun-bleaching, though the dark spotting remains visible. Collectibility grade: Good (standard beach specimen).
Interesting Facts
The name 'Dye Shell' comes from the fact that these snails, like many in the Muricidae family, produce a mucus secretion that turns purple when exposed to oxygen and sunlight. In ancient times, related species were used to produce 'Tyrian Purple' dye.
Ecological Role
A carnivorous predator that feeds on bivalves such as oysters and mussels, as well as barnacles. It uses its radula and acidic secretions to drill holes through the shells of its prey.
Similar Species
Stramonita haemastoma (Red-mouthed Rock Shell), which is typically larger with more pronounced nodes and a deeper red/orange aperture, and Thais deltoidea (Deltoid Rock Shell), which has a more triangular shape.
Beach Finding Tips
In Myrtle Beach, look around the rocky groins and jetties at low tide. They are often found washed up in the shell lines immediately following a storm or high energy surf.
Notes
Myrtle Beach SC